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Determining the road traffic accident hotspots using GIS-based temporal-spatial statistical analytic techniques in Hanoi,Vietnam

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Geo-Spatial Information Science 2020年第2期23卷 153-164页

作者： Khanh Giang Le Pei Liu Liang-Tay Lin College of Construction and Development Feng Chia UniversityTaichungTaiwanChina Faculty of Civil Engineering University of Transport and CommunicationsHanoiVietnam

This study applied GIS-based statistical analytic techniques to investigate the influence of accident Severity Index(SI)on temporal-spatial patterns of accident hotspots related to the specific time intervals of day and seasons.Road Traffic Accident(RTA)data in 3 years(2015-2017)in Hanoi,Vietnam were used to analyze and test this approach.Firstly,the RTA data were divided into four seasons in accordance with Hanoi's weather conditions and the time intervals such as the daytime,nighttime,or peak hours.Then,the Kernel Density Estimation(KDE)method was applied to analyze hotspots according to the time intervals and seasons.Finally,the results were presented by using the comap technique.This study considered both analyses with and without SI.The accident SI measures the seriousness of an accident.The approach method is to give higher weights to the more serious accidents,but not with the extremely high values calculated on a direct rate to the accident expenditures.The results showed that both analyses determined the relatively similar hotspots,but the rankings of some hotspots were quite different due to the integration of SI.It is better to take into account SI in determining RTA hotspots because the gained results are more precise and the rankings of hotspots are more accurate.From there,the traffic authorities can easily understand the causes behind each accident and provide reasonable solutions to solve the most dangerous hotspots in case of limited budget and resources appropriately.This is also the first study about this issue in Vietnam,so the contribution of the article will help the traffic authorities easily solve this problem not only in Hanoi but also in other cities.

关键词： Road Traffic Accident(RTA) hotspot GIS temporal-spatial analysis Kernel Density Estimation(KDE) Severity Index(SI)

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Effect of Varying Temperature and Oxygen on Particulate Matter Formation in Oxy-Biomass Combustion

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Energy Engineering 2022年第3期119卷 863-881页

作者： Chen Wang Cicilia Kemunto Mesa Samuel Bimenyimana Nathan Bogonko George Adwek Yiyi Mo Godwin Norense Osarumwense Asemota Changfu Yuan Yaowen Chen Changtai Li Etienne Ntagwirumugara Aphrodis Nduwamungu Fujian Provincial Higher–Educational Engineering Research Centre of Intelligence and Automation in construction College of Civil EngineeringHuaqiao UniversityXiamenChina Kenya Industrial Research and development Institute NairobiKenya Hello Renewables Ltd.KigaliRwanda Mount Kenya University ThikaKenya African Centre of Excellence in Energy for Sustainable development University of RwandaKigaliRwanda Morayo college NairobiKenya Fujian Baichuan construction Technology Co. Ltd.XiamenChina Haoqi(Xiamen)construction Technology Co. Ltd.XiamenChina University of Rwanda College of Science and TechnologyKigaliRwanda

Offsetting particulate matter emissions has become a critical global aim as there are concerted efforts to deal with environmental and energy poverty challenges.This study consists of investigations of computing emissions of particulate matter from biomass fuels in various atmospheres and temperatures.The laboratory setup included a fixed bed electric reactor and a particulate matter(PM)measuring machine interfaced with the flue gas from the fixed bed reactor combustion chamber.The experiments were conducted at seven different temperatures(600℃-1200℃)and six incremental oxygen concentrations(21%-100%).Five biomass types were studied;A-cornstalk,B-wood,C-wheat straw,D-Rice husk,E-Peanut shell,each pulverized to a size of approximately 75 microns.The study shows that PM emitted during char combustion is consistently higher than that emitted during the de-volatilization.During de-volatilization,increase in temperature leads to linear decrease in PM emission between atmospheres of 21%O_(2)to 50%O_(2),thereafter,between 70%O_(2)to 100%O_(2);increase in temperature leads to a rise in PM emission.The average PM formation from all the five considered biomass is relatively comparable however,with differing atmospheres and temperatures,the fibrous and low-density biomass forms more PM.During char combustion,the study shows that at oxygen levels of 21%,70%,90%and 100%,increase in temperature leads to increased PM emission.The increase in oxygen concentration and temperature increases the rate of combustion hence diminishing the time of combustion.

关键词： Oxy-fuel combustion particulate matter(PM) volatiles char combustion

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An improved LuGre model for calculating static steering torque of rubber tracked chassis

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Defence Technology（防务技术） 2022年第5期18卷 797-810页

作者： Kang Liang Qun-zhang Tu Xin-min Shen Zhong-hang Fang Xuan Yang Yong Zhang Hui-yu Xiang college of Field Engineering Army Engineering University of PLANanjing210007China State Key Laboratory of Intelligent Manufacturing of Advanced construction Machinery Xuzhou Construction Machinery GroupXuzhou221004China

Tire and rubber track interchangeable chassis combines the advantages of tire and rubber track,which can greatly improve the maneuverability of military construction machinery.However,there is almost no effective calculation model for the real-time static steering torque.When the relative sliding speed is greater than 0.01 m/s,the influence of friction heating can not be ignored.An improved LuGre model is established to calculate the static real-time steering torque of tire and rubber track interchangeable chassis.Firstly,the friction heating model between rubber and ground is established.Combined with the influence of temperature on the dynamic performance of rubber material,the influence of friction heating on the stiffness and friction coefficient of rubber track is analyzed,and the improved LuGre friction model is established.The steering torque of tire and rubber track interchangeable chassis is affected by rubber material properties,steering speed,pavement type,and ambient temperature.Compared with the original Lu Gre model,the improved LuGre model captures the change in friction torque during multiple in-situ turns due to frictional heating.The error with the experimental data is small,which verifies the effectiveness of the improved LuGre model.

关键词： Rubber track Static steering torque Friction model Chassis Maneuverability Vehicle

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Mechanisms underlying attenuation of apoptosis of cortical neurons in the hypoxic brain by flavonoids from the stems and leaves of Scutellaria baicalensis Georgi

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Neural Regeneration Research 2014年第17期9卷 1592-1598页

作者： Guangxin Miao Hongxiang Zhao Ke Guo Jianjun Cheng Shufeng Zhang Xiaofeng Zhang Zhenling Cai Hong Miao Yazhen Shang Institute of Traditional Chinese Medicine Chengde Medical College/Key Subject Construction Project of Hebei Provincial College/Hebei Province Key Laboratory of Traditional Chinese Medicine Research and Development Department of Anesthesiology Affiliated Hospital of Chengde Medical College

Flavonoids from the stems and leaves of Scutellaria baicalensis Georgi, an antioxidant, markedly improve memory impairments and neuronal injuries. In the present study, primary cortical neurons of rats were exposed to potassium cyanide to establish a model of in vitro neural cell apoptosis. Inhibition of apoptosis by flavonoids from the stems and leaves of Scutellaria baical- ensis Georgi at concentrations of 18.98, 37.36, and 75.92 gg/mL was detected using this model. These flavonoids dramatically increased cell survival, inhibited cell apoptosis and excessive pro- duction of malondialdehyde, and increased the activities of superoxide dismutase, glutathione peroxidase, and Na＋-K＊-ATPase in primary cortical neurons exposed to potassium cyanide. The flavonoids from the stems and leaves of Scutellaria baicalensis Georgi were originally found to have a polyhydric structure and to protect against cerebral hypoxia in in vitro and in vivo models, including hypoxia induced by potassium cyanide or cerebral ischemia. The present study suggests that flavonoids from the stems and leaves of Scutellaria baicalensis Georgi exert neuroprotective effects via modulation of oxidative stress, such as malondialdehyde, superoxide dismutase, glutathione peroxidase and Na＋-K＋-ATPase disorders induced by potassium cyanide.

关键词： nerve regeneration brain injury Scutellaria baicalensis Georgi flavonoids potassium cyanide apoptosis oxidative stress Na＋-IC-ATPase neural regeneration

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Non-Markovianity Measure Based on Brukner–Zeilinger Invariant Information for Unital Quantum Dynamical Maps

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Communications in Theoretical Physics 2017年第3期67卷 255-260页

作者：贺志朱烈强李莉 college of Physics and Electronics Hunan Province Cooperative Innovation Center for The Construction and Development of Dongting Lake Ecological Economic Zone Hunan University of Arts and Science Changde 415000 China

A non-Markovianity measure based on Brukner–Zeilinger invariant information to characterize nonMarkovian effect of open systems undergoing unital dynamical maps is proposed. The method takes advantage of non-increasing property of the Brukner–Zeilinger invariant information under completely positive and trace-preserving unital maps. The simplicity of computing the Brukner–Zeilinger invariant information is the advantage of the proposed measure because of mainly depending on the purity of quantum state. The measure effectively captures the characteristics of non-Markovianity of unital dynamical maps. As some concrete application, we consider two typical non-Markovian noise channels, i.e., the phase damping channel and the random unitary channel to show the sensitivity of the proposed measure. By investigation, we find that the conditions of detecting the non-Markovianity for the phase damping channel are consistent with the results of existing measures for non-Markovianity, i.e., information flow, divisibility and quantum mutual information. However, for the random unitary channel non-Markovian conditions are same to that of the information flow, but is different from that of the divisibility and quantum mutual information.

关键词：量子动力学信息计算马尔科夫性单位非马尔科夫动态地图噪声信道马尔可夫

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A statistical approach to determine 2D optimal equivalent linear parameters with application to earthquake engineering

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Earthquake Engineering and Engineering Vibration 2012年第3期11卷 415-425页

作者： Su Liang Xiao Nan Wang Yi college of Civil Engineering and Architecture Zhejiang University Hangzhou 310058 China China Aviation Planning and construction development Co. Ltd Beijing 100120 China

The equivalent linearization method approximates the maximum displacement response of nonlinear structures through the corresponding equivalent linear system. By using the particle swarm optimization technique, a new statistical approach is developed to determine the key parameters of such an equivalent linear system over a 2D space of period and damping ratio. The new optimization criterion realizes the consideration of the structural safety margin in the equivalent linearization method when applied to the performance-based seismic design/evaluation of engineering structures. As an application, equations for equivalent system parameters of both bilinear hysteretic and stiffness degrading single-degree-of- freedom systems are deduced with the assumption of a constant ductility ratio. Error analyses are also performed to validate the proposed approach.

关键词： equivalent linearization particle swarm optimization structural safety nonlinear displacement response performance-based engineering

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大跨度混凝土拱桥原型与模型时变行为对比

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Journal of Central South University 2022年第5期29卷 1565-1577页

作者：王永宝秦鹏举刘志华张翛毛敏 college of Civil Engineering Taiyuan University of TechnologyTaiyuan 030024China Shanxi Transportation Technology Research&development Co.Ltd.Taiyuan 030027China Transportation Industry Key Laboratory of Highway construction and Maintenance Technology in Loess Region Taiyuan 030027China

北盘江大桥为一座主跨为445 m,矢高为100 m的无铰拱桥,是中国已建的最大跨度劲性骨架混凝土拱桥。为研究该桥施工过程的合理性和成桥后的长期性能,开展了模型试验研究,但当考虑长期性能后,原型和模型桥测试的变形和应力比例不符合线弹... 详细信息

北盘江大桥为一座主跨为445 m,矢高为100 m的无铰拱桥,是中国已建的最大跨度劲性骨架混凝土拱桥。为研究该桥施工过程的合理性和成桥后的长期性能,开展了模型试验研究,但当考虑长期性能后,原型和模型桥测试的变形和应力比例不符合线弹性比例关系。因此,本文建立了原型桥与模型桥的三维有限元模型,用实测数据验证有限元模型的正确性;对比了原型桥与模型桥在弹性和考虑温度与收缩徐变耦合效应后的位移、应力结果,并对其长期变形行为进行参数分析。研究结果表明:当考虑有效温度和混凝土收缩徐变效应后,原型桥和模型桥的有限元分析结果与实测结果吻合较好;原型桥与模型桥在不同施工和成桥阶段的位移和应力相似比不再完全满足7.5和1.0的要求;混凝土收缩徐变预测模型和温度变化历程均会对原型桥与模型桥的位移比例产生较大影响。

关键词：混凝土拱桥时变行为有限元模型试验劲性骨架

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Design and validation of high speed true random number generators based on prime-length ring oscillators

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The Journal of China Universities of Posts and Telecommunications 2015年第4期22卷 1-6页

作者： Liao Ning Jiang Ding Bai Chuang Zou Xuecheng Swan college Central South University of Forestry and Technology Hunan Lianzhu Expressway construction and development Co. Ltd School of Optical and Electronic Information Huazhong University of Science and Technology

This paper presents a wide supply voltage range, high speed true random number generator（TRNG） based on ring oscillators, which have different prime number of inverters. And a simple Von Neumann corrector as post processing is also realized to improve data randomness. Prototypes have been implemented and fabricated in 0.18 μm complementary metal oxide semiconductor（CMOS） technology with a wide range of supply voltage from 1.8 V to 3.6 V. The circuit occupies 4 500 μm2, and dissipates minimum 160 μW of power with sampling frequency of 20 MHz. Output bit rate range is from 100 kbit/s to 20 Mbit/s. Statistical test results, which were achieved from the die Hard battery of tests, demonstrate that output random numbers have a well characteristic of randomness.

关键词： true random number generator,ring oscillators,arbiter,Von Neumann corrector

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Reliability analysis of retractable drill bit with air reverse circulation used for drilling while casing

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Global Geology 2023年第1期26卷 47-56页

作者： WANG Minqi YIN Qilei CHEN Baoyi QI Bo BO Kun CAO Pinlu college of construction Engineering Jilin UniversityChangchun 130026China

Casing-while-drilling(CWD)with down the hole(DTH)hammer drilling technology has been widely used in unconsolidated formations,due to its advantages in protecting the borehole wall,excellent rock cuttings capacity,and fast penetration rate in hard rock.As an important component of the CWD system,the structure of the retractable drill bit needs not only to ensure to form stronger reverse circulation,but also to be expandable or retractable as needed,otherwise the drill bit cannot be lift and put down smoothly in the casing,and may lead to drilling accidents.This paper developed a new type of reverse circulation DTH hammer drill bit used for CWD drilling technology.The retractable performance of this type of drill bit is studied using ADAMS software.The results show that it is smoothly expandable and retractable as designed under the conditions of the weight of the bit(WOB)of 0.5–2.0 t and the rotation speed of 30–60 r/min.To investigate the reverse circulation effect of the drill bit,Fluent software was used to simulate the flow characteristic inside it.The simulation results indicated that it can form strong reverse circulation,and the entrainment ratio h can reach 9.5%.

关键词： DTH hammer drilling air reverse circulation casing-while-drilling retractable drill bit

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文化遗产的旅游开发潜力及障碍因子——基于湘西传统音乐的实证

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Journal of Geographical Sciences 2024年第2期34卷 309-328页

作者：张先永彭保发周璐璐鲁春阳王亚力刘锐向慧 college of Music and Dance Hunan University of Arts and ScienceChangde 415000HunanChina college of Geography and Tourism Hunan University of Arts and ScienceChangde 415000HunanChina college of Geographical Sciences Southwest UniversityChongqing 400715China college of Surveying and Mapping and Urban Spatial Information Henan University of Urban ConstructionPingdingshan 467036HenanChina college of Tourism Management Chaohu UniversityHefei 238000China Institute of Green Low-Carbon development Southwest UniversityChongqing 400715China

Traditional music is an important component of cultural heritage.However,studies have scarcely explored the tourism development potential and the obstacle factors of traditional music.This study takes Xiangxi as the research site,constructs an evaluation index system,and utilizes survey and geographical methods.The major research results are as follows:First,the average potential of resource endowment,tourism industry development,and socio-economic conditions are 0.28,0.36,and 0.24,respectively.The potential of resource endowment is higher in the west and lower in the east,that of tourism industry development is higher in the north and south and lower in the center,and that of socio-economic conditions is higher in the south and lower in the north.Second,the comprehensive potential is 0.29,which is higher in the northwest and southwest regions.Coordination in most administrative units is at a medium level,and most regions have obvious advantages in resource endowment.Third,the primary obstacle factor is socio-economic conditions(39.21%),followed by resource endowment(30.73%)and tourism industry development(30.06%).The administrative units can be classified into four groups:socio-economic condition obstacle,resource endowment and tourism industry development obstacles,resource endowment and socio-economic condition obstacles,and tourism industry development and socio-economic condition obstacles.The highest priority goals for Xiangxi involve economic development and the integration of modern technologies to stimulate passenger flow.For reg traditional music items(eastern area of Xiangxi),tourism development should be restrained and other resources with stronger inherent advantages should be exploited.This study explored the quantification of traditional music tourism potential,representing a novel breakthrough in this field of research.The indicator system and research methods used in this study can provide guidance and methodological references for cultural heritage research.The suggestions proposed in this artic

关键词： cultural heritage tourism development potential obstacle factors traditional music Xiangxi

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